Drill fluting machine



Oct. 22, 1940. H. E. MATTHEWS DRILL FLUTINGMACHINE Filed Feb. 25, 1958 4Sheets-Sheet l JQveor: @Hanf-@Maya Oct. 22, 1940. H. E. MATTHEWS l DRILLFLUTING MACHINE sheets-sheet 2 Filed Feb. 23, 1938 Oct. 2 2, 1940.` H.E. MATTHEWS DRILL FLUTING MACHINE 4 sneetssheer s Filed Feb. 2s, 1938 Hmm von il@ m @@n@ OLV@ C Oct- 22, 1940. H. E. MATTHEWS DRILL FLUTINGMACHINE Filed Feb. 23, 1958 4 Sheets-Sheet 4 Alli Patented Oct. 22, 1940DRILL FLUTING MACHINE y Harlan E. Matthews, Buchanan, Mich., assignor toClark Equipment Company, Buchanan, Mich., a rcorpoiation of MichiganApplication February 23, 1938, Serial No. '191,992

` 13 Claims.

This invention relates to a drill fluting mechanism, and moreparticularly is directed toy apparatus of a semi-automatic nature forforming the flutes in small drill blanks and the like by 5 the use of asingle formed milling cutter in place of the two conventional formedcutters mounted angularly to each other andv to the drill blank.

It has been difficult, in previous types of mechanisms for formingiiutes in drills, to obtain accurate formation of these flutes due tothe impossibility of producing two formed cutters of exactly the samecontour and because of the inability of an operator to so adjust twocutters in angular relationship to each other and to the drill being cutVas to produce a drill of absolute uniformity. v k

It has also been customary, so far as I am aware, to form the flutes insmall drill blanks by means of hobs or the like, and the size of theblanks was such that inaccurate fluting occurred. So far as I am aware,no one has attempted to form such utes by means of feeding a drillthrough automatic feeding mechanism to a rotating cutter with automaticmeans for indexing the blank from the cutter, reindexingthe same,v

again feeding it to the cutter and then again returning it from cuttingposition and declutching the drive mechanism. This therefore requiresthe attention of an operator only for the insertion of a drill blankinto the mechanism, and the removal of the fluted blank therefrom. One-operator is therefore capable of supervising the operation of aplurality of such mechanisms, which greatly reduces the cost of thedrills.

One of the primary objects of the present invention is to provide meansfory gripping the drill blank in projecting position and then feedingthe same along a predetermined helix whereby it is moved axially andsimultaneously rotated asit passes into engagement with the cutter. Asuitf able clutch mechanism is provided for stopping the forwardmovement of the blank at apredetermined point and simultaneously raisingthe drill cutter out of engaging position. The blank is then returned,reindexed for the second flute and again fed into the cutter whereuponthe clutch means again operatesto return y.the blank the drill so thatthe flutes are formed at pre- (Cl. S-15.1)

to initial position and simultaneously declutches the actuating means.

One of the features of the present invention is the provision of alifting cam associated with thev cutter for producingsimultaneousraising movel5 ment of the cutter as the drill isfedthereto, thereby producing the desired ,decrease in depth of theflute as itapproaches the shank portion of the drill. This same cammingmechanism operates to raise the cutter out of engagement with 10 theblank as the machine reverses for the re- 'n indexing operation.

Another advantage secured by the present invention is Athe provision ofa cutter so mounted with respect to the axial direction of the blank 15that the center of rotation of the cutter shaft4 always lies in avertical plane throughk the axis l f of the blank, although the cutteritself may assume any desired angularity with respect to this blank. v

`Still another feature of the present invention is the provision of aclutch mechanism for clutching the blank feeding means to a prime moversuch as an electric motor orthe like, which is automatically disengagedupon the completion of k25 a predetermined number of flute forming`operations.

Still another feature of the present invention is the provision of adriving shaft mounted upon eccentric bearing journals and controlled bya 3o friction clutch 4so that upon `the feeding mechanism reaching itsinward limiting position, the clutch is released to allow a halfrevolution of the shaft journals, thereby placing theshaft in alaterally offset position in driving engagement 35 through a separategear train to effect ,reverse kmovement-of thefeeding mechanism forWithdrawing the blank from cutting position and re-` indexing the same.

Still another object of the present invention is 40 to provide acammingmechanism operable upon' return of the feeding mechanism to initialposition for releasing the indexing engagement em- -ployed in ther firstflute forming operation, and f automatically. reindexing the mechanismfor 45 forming the second flute.

Another feature of the present invention is the absolute uniformity ofthe completed drill, obtained by cutting each flute with the samecutter, thus producing twoflutes exactly degrees 50 apart with the webor solid central portion of the drill in the exact center of the drillblankregardless of the setting of the cutter in relation .to-the drill.An advantage of the above feature is that owing to the uniformityiof theamount rof metal 55 :removed from the flutes of the drills by themilling operation, they suffer much less distortion during the extremehigh heats necessary in the hardening and drawing operations, withresultant saving in subsequent straightening operations.

Another feature and distinct advantage of the present invention is theprovision of means for effecting relatively high speed reverse movementof the feeding mechanism while yet effecting the proper relativelyslower feeding speed during the flute forming operation.

In connection with this latter mechanism, I provide a second clutchoperated by the feeding mechanismas it reaches its outer limitingposition for effecting a half revolution of rotation of the eccentricbearing journals of the main driving shaft, thereby restoring theoriginal gear drive for producing inward movement of the feedingmechanism.

Another feature of the present invention resides in the provision of astop means operated by the feeding mechanism for de-energizing theentire machine in the event that the clutch for reversing the movementof the feeding mechanism fails to operate.

Still another feature of the invention resides in the provision of alubricating pump operated by the same prime mover that operates thefeeding mechanism, and which forces lubricant over the cutter and drillblank during' the cutting operation.

Other objects and advantages of the present invention will be moreapparent from the following detailed description Which, taken inconjunction with the accompanying drawings will disclose to thoseskilled in the art the particular construction and operation of apreferred form of the present invention.

In the drawings:

Figure 1 is a rear perspective view of the essential portions of thedrill fluting mechanism;

Figure 2 is a front perspective View of the mechanism shown in Figure 1;

Figure 3 is an end perspective view of the driving mechanism and feedingmeans;

Figure 4 is a diagrammatic view showing the gear relationships ofvarious portions of the mechanisms; and

Figure 5 is a sectional view taken substantially on line 5 5 of Figure 4showing the indexing mechanism.

Referring now in detail to the drawings, the base of the machine isshown generally at Ill and mounted thereon is an electric motor I2 asshown in Figure 2. This motor is provided with the double pulleys I3 andI4 mounted on the drive shaft thereof, the pulley i3 being connectedthrough the belt I5 to a large pulley It mounted on the end of a shaftil which is supported in suitable journals I8 and I9 for rotation.

The operation of the motor I2 is controlled through means of the switch23 shown inFigure 2 and mounted on a suitable pedestal 22 secured to thebase I0. Mounted on the shaft I I is a small pulley 23 adapted to drivethe belt 24 connected to the drive shaft 25 of a lubricant pumpindicated generallyv at 26. The lubricant pump 26 has its inlet 21connected to the base of the center supporting pedestal 28 and has anoutlet connection 29 which, through the conduit 30 and valve 32, isadapted to supply cutting oil to the cutter 33.

From the cutter 33 the oil trips into the sump 34` from which it isdrained through the spout 35 into the base of the stand 28 and thenreturns to the inlet of the pump 25. The shaft Il extends through aclutch housing 36 and is provided with a small pinion gear 3l Within thehousing. The housing is also adapted to provide a rotatable support fora countershaft 38 upon which is mounted the gear 39 driven from thepinion gear 31. A similar pinion 45 on the shaft 38 is adapted to driveback to the gear 42 which is free for rotation on the shaft Il. Anoutput shaft 43 extends through the opposite side of the housing 36 andis provided with a suitable clutch collar M connected to the clutchoperating lever 45 for axial movement on the shaft Il@ into and out ofengagement with the clutch teeth 46 carried by the gear 42.Consequently, a double reduction of the drive from the shaft Il' to theshaft 43 is effected through the clutch d4 connected to the lever 45.The lever 45 is mounted for rotation about a pivot 4l and at its upperend is provided with a handle portion 48 adapted to be controlled by theoperator. The lower end of the lever beneath the pivot fil is providedwith an ear 49 receiving one end of a tension spring 50, the 4oppositeend which is secured to a fixed part of the stand i l) (not shown).

A suitable arm 52 is pivotally mounted on the top of the clutch housing36 by meansof the stud 53, and is provided with the spring 54 normallyurging it against the lever 45 so that it follows the lever when thelever is shifted into clutch position. The arm 52 is held againstreverse rotation about the stud 53 by means of the pivotally mountedlatch 55 which has a lug 55 adjacent one end thereof adapted to engagein a suitable detent in the arm 52 to prevent reverse rotation thereof.A suitable leaf spring 5l normally holds the latch 55 in position toeffect locking of the arm 52 against movement after the clutch has beenshifted into clutch position.

The end of the shaft I3 is provided with the sprocket wheel 6I! which isconnected through the sprocket chain 62 to a second sprocket wheel 63carried on the main driving shaft 64, as shown more clearly in Figure 3.Mounted on the outer side of the sprocket wheel 6D is an idler arm 65carrying the sprocket idler 66 for maintaining the proper tension on thechain 62.

The drive shaft 64 is mounted in eccentric bearing journals indicatedmost clearly in Figure 1 by reference numerals 6l and 68 which arenormally held against rotation by means of a friction clutchingmechanism enclosed in subbase III, the details of which form no part ofthe present invention, and therefore it is not believed necessary todescribe the same. The bearing journals 61 and 68 are mounted in asupport 'II which is secured to the frame Il! in any suitable manner,and the amount of eccentricity is indicated by the difference inposition of the center of the bearing journals as indicated at A and A'in Figure 4. A suitable connector plate 69 connects the journals 61 andB8 of the eccentric bearing assembly so that they are rigidly supportedfor conjoint movement upon release of the friction clutching mechanism.A relatively small diameter driving gear of considerable axial extent isformed on the main shaft as inldicated at 10, and rotates on bearingswithin the journals 6'I and 68. Upon release of latches It!) and I6'I bymeans of the friction clutch, the pinion gear 'Hl will rotate with theeccentric journals v6'! and 68. Also secured to the main shaft is alarge gear drum 12 keyed for conjoint rotation therewith.

Referring now in more detail to Figures 3 and 4, it will be noted thatwhen the pinion 10 is in a position such that its center is rotated, asindicated at A in Figure 4, the'drum gear 12 isin meshing engagementwith an idler gear 13 mounted upon shaft 14, which in turn meshes withan intermediate gear 15 mounted upon shaft 15 that, at itsI oppositeside, is in meshing engagei ment with a drum gear 11 mounted on a shaft18. The drum gear is adapted torotate in the direction indicated by thearrow in Figure 4, and consequently produces clockwise rotation of thegear 11. It will be noted that the shaft 18 is supported on a suitablejournal 1B and is provided adjacent its outer end with a bracket 19adapted to supporta pivot pint@ mounting the latch releasing lever 82thereon. The lever 82 is in the form of a bell crank, .one end of which,indicated at 83, extends between the forked end lever 55. This samejournal 1B extends downwardly and forms an end journal for the outerends of the shafts 14 and 15 as clearly shown in Figure 3, and is alsosupported upon the base or frame I0. y

When the gear member 12 is'in itsy opposite position, thatv is, when itscenter is at a point indicated at A' in Figure 4, it is adapted to havemeshing engagement with the indexing gear 85 carried on the spindle 85.It will also be noted that the gear 11 is at all times inV meshingengagement with the feed gear V81 which is connected to a sleeve 8Bextending through a longitudinally projecting journal 89 formedladjacent the top of the stand 28 as shown in Figures l and 2. Thefeeding sleeve 88 is provided with a spiral thread or recess 90, thepitch 4of which forms the lead for the blank, The sleeve88 is movedlongitudinally within the journal 89 by the engagement of a bronze pintherewith within the journal 89, the pin being formed at the end of thestud 92 which is supported in the boss 93 formed on one lateral side ofthe journal.

Considering nowagain Figures 1 and 2, it will be noted that the spindle86 extends through the sleeve 88 and at its opposite end is providedwith a collet portion 94 containing gripping jaws for gripping the drillblank 95. These jaws are actuated by the knurled spindle 95 lat theopposite end of the collet 94 which is rotated in one direction totighten the drill in position, and is rotated in the opposite directionto loosen the drill for removal. Y

Mounted on the frame I0 is a bar member 98 having an elongated slot99'therein whereby it may be longitudinally adjusted with respect to theframe by means of the locking nut |00. The arm 98 has a verticallyextending portion |02 which, at its upper end is provided with a pin |03adapted to receive at the inner end thereof the camming arm |54 havingthe cam surface |05 secured thereto. This arm is rnounted'forv pivotalmovement with respect to the arm portion |02 and is normally restrainedin the position shown in Figures 1, 2 and 3 by means of the tensionspring |55 secured to the arm and to the arm portion |02. The gear 85 isprovided with two indexing plungers |91 and |08 mounted in cylindricalsupports |09 threaded into suitable openings in the gear 85 andindicated in detail in Figure 5.V The plungers |51 and H08 have reducedportions I I0 projecting through the gear 85 and normally urgedoutwardly therefrom bymeans of the spring |12,

Th'ege'a'r' 81y is provided 'with acooperating indexing plunger. l|4mounted ina support I 5 extendingithrougl'i the gear 81 .and clampedthereto by the nut` I I6 en-gaging the projecting threaded shank.` Asuitable spring I I1 retained in the axial recess inthe support.l |5normally urges the plunger ||4 toward the gear 85 The projecting end II8 ofthe plunger I |4, when in indexed position is adapted to extendintothe recess or bore of one of the supports |09 and contacts the inner endof the plunger 01; f

However, whenthe rotation of the gear 85 is such as to forcetheprojecting ends of either the plunger |01 or |00 inwardly by engagementwith the cam surface |05`of the arm |04, the plunger is forcedinwardly.into position to disengage the projecting'end H8 ofthe plunger ||4 fromthe gear 85.` As a result,v the gear 81 is released for relativerotation with respect to the gear 85, and the gear 85 is adapted to moveinto position to bring the opposite plunger opening Ithereof intoalinem'ent with the plunger endl I8 of the plunger I4, Since cam member|04 swings back, this end immediately enters into the recess formed inthe support |09 and ythus locks the two gears 85 and 81 together for.conjoint rotation into angular relationship'of 180 degrees with respectto their initially locked position.'

Whenever the two gears 85 and 81 are locked together thesleeve 88 willproduce longitudinal movement of thexspindle 86 upon rotation of thegear 81 since the spindle and sleeve are correspondingly locked`together for conjoint rotation. Consequently, the longitudinal movementof the sleeve 88 will produce a corresponding axial movement of thedrill blank 95,. either into or out of engagement with the cutter 33.

Reference is now made to Figures 1 and 2A to show the mounting of thecutter mechanism for forming the fluted end in the drill blank. A post(not shown) carrying the hardened drill guide (not shown) at its upperend extends vertically through lthe base I0 to the upper end(immediately below the drill bushing) to which is secured the sump 34surrounding the cutter mechanism. This post has mounted thereon a sleeve|20 carrying 'at the-lower end and integral with it the graduated flange|34 which is secured by clamping screws |35 to the base I0 butvisotherwise free to rotate about the cutter post. Mounted upon sleeve |20is the member |22 which has a sliding fit on sleeve |20 and is preventedfrom rotating with respect thereto by the key |32 which engages a' slot(not shown) in sleeve I 20. The member |22 is free to move axially onsleeve |20 but is normally held in contact with cam bar |44 through thelateral .extension |49 and the spring 43. Integral with the member |22is vthe web I2@ carrying at its lower end the transverse shafts |25 uponthe opposite ends of-which are mountedthe pulleys |26- Adjacentto itsupper end the web |24 provides `a support for the longitudinallyextending journal |21 through which extends the shaft 28 having thepulley l29 secured thereto above the pulleys |25. At its opposite endthe shaft E28 is provided with `a suitable adjusting clamp ynut for nangle of the cutter`33,"the member |22 may be rotated with respect tothecenter line of the drill by loosening the clamp screws |35 in the flangeplate |36 carried by the sleeve |28 and relocating the cutter mechanismby the angular graduations on the ange |34. The pulleys |26 and |29 areadapted to be engaged by a driving belt |31 which is trained thereof andwhich extends beneath the base plate I and under the pulley wheel |38 tothe second pulley I4 on the motor drive shaft of the motor I2. Thus, theshaft |28 is driven from the motor I2v conjointly with the drivinglmechanism including the shafts |1 and 43.

It will be noted that the lower end of the member |22 is provided with aflange portion having the lateral extension |48 forming a pair of earsbetween which is clamped a lifting plate |42 normally engaged by aspring |43 for pulling the member |22, and consequently the shaft |28downwardly to locate the sameY with respect to a cam plate or lifter|44. 'Ihe lifter |44 is longitudinally tapered and is forced beneath theplate |42 by movement of the gear 81 to produce raising of the cuttingmechanism as the feeding mechanism feeds the blank thereto so that thedepth of cut of the flute is slowly decreased as the blank is fed intothe cutter. The cam arm |44 is connected to a cross head |45 which hasan extending shaft |46 supported by the journal (not shown)r inside ofthe stand 28. The shaft |46 projects through a suitable journal insideof stand 28 and has a projecting end portion 58 adapted to be engaged bythe lateral face of the gear 81. The projecting portion |58 is providedwith a serrated surface on one lateral face thereof which is adapted tobe engaged by the rocking surface of a locking member |52 in the formofv a bell crank pivotally mounted on the side of the stand 28, andhaving its other arm portion extending down beneath the pinion and crosssection 69 in such manner that when the eccentric bearings 61 and 68 arereleased so that the member 68 rotates to its lowermost position, itrocks the arm |52 into pressure engagement with the serrated surface ofthe shaft to lock the cam member |44 in xed position against the tensionspring |55 which is connected between the cross head |45 and a fixedportion of the mechanism.

Mounted on a bracket |56 projecting from the side of the stand 28 is asafety switch mechanism enclosed within the housing |51. This mechanismhas a plunger |58 projecting therefrom toward the gear 81 and isadjustable with respect to the gear 81 by means of the adjusting screw|59 carried by an upwardly extending arm portion |66 of the bracket |56.This safety switch mechanism is for the purpose of shutting off themotor I2 if the gear 81 should move beyond a predetermined positiondetermined by the length of flute to be cut in the drill blank. It willbe noted from Figures 1 and 2 that a plunger |85 is provided projectingfrom the end face of the sub-base |1|, and which is disposed in the pathof movement of the gear 81. This plunger |65 is for the purpose ofoperating the friction clutch controlling the locking of the bearings 61and 68 in alternate positions. When the gear 81 engages the plungerwhich forces the same slightly inwardly, the latch is released and thebearings 61 and 68 and member 69 rotate through a half revolution tomove the pinion 10 out of engagement with the gear 81 and downwardlyinto position such that the gear drum 12 engages the gear 13. 'I'hereturn of the bearings 61 and 68 to their initial position is providedby engagement of the gear 81 with the adjusting knurled nuts |61 carriedon a shaft |68 disposed "out of the peripheral path ofthe gear 81 withthe edge of the gear engaging the nuts |61 to move them to the left asshown in Figure 1, thereby drawing the shaft |68 to the left andconsequently again releasing the friction clutch to allow the bearings61 and 68 and the pinion shaft 58 to rotate through part of a secondhalf revolution into almost their initial position, thereby placing thegear 85 in mesh' with the gear drum 12.

Considering now the operation of the mechanism when it is desired to utea gear blank, the motor I2 is first started by means of the controlswitch 28. This produces rotation of shaft |1 and also rotation of thecutter shaft |28 through the belt drives I and |31. A drill blank 95 hasbeen locked in the collet 64 by rotation of the knurled locking spindle86, and the mechanism is disposed with the sleeve 88 in its outertheplunger ||8 in the recess of the support |89 of the gear 85.

The clutch 48 is then rotated from the position shown in the drawingsinto a position to engage the clutch collar 44 with the clutch teeth 46of gear 42. 'I'his produces rotation of shaft and consequently, rotationofthe sprocket wheel 63 in a counter clockwise direction. This producescounter clockwise rotation of the gear drum 12, and consequently,clockwise rotation of gears 85 and 81. The eccentric journals 61 and 88are at this point in an intermediate position, with gears 10 and 81 outof engagement.

However, the gear 85 soon leaves the gear drum 12 due to the forwardtravel of sleeve 88 by engagement of the pin 92 in the thread 68. As aresult, the eccentric journals move up to limiting position, rotatingpinion gear 18 into mesh with gear 81 to drive the gear 81 for feedingthe drill blank 95 into the cutter 33. During this time the pump 26 ispumping suitable lubricant over the cutter through the conduit 38, andthis lubricant is being drained into the base of the stand 28 andreturned to the pump. The gear 81 at the same time is in mesh with gear11 and consequently rotates the gear vtrains 11, 15 and 18.

However, since the drum gear 12 is out of engagement with gear v13, thisgear train merely idles during the feeding operation. As the gear 81nears the 4end of the feeding movement the lateral face thereof engagesplunger |65 forcing the same inwardly, and thereby releasing thefriction clutches holding bearings 61 and 68. These bearings are thenfree to rotate, and consequently rotate the pinion 18 and gear drum 12into a position having a center of rotation indicated at A in Figure 4.As a result, driving engagement of the pinion with the gear 81 isreleased and no further feeding movement is produced.

During this feeding movement, the lateral face of the gear 81 has alsobeen forcing the shaft |50 to the right as viewed in Figure l,consequently forcing the camy |44 beneath the plate |42 to progressivelyraise the collar |22 and consequently decrease the depth of flute beingcut. As the bearings 61 and 68 are released by the operation of plunger|65, the rotation of the pinion 18 and member 69 into the lower positionrocks` the bell crank |52 into position to engage the serrated plate inposition to maintain the cutter Mheaddn raised position. It should bevpointed outthat the rear portion of the cam bar |44 hasan increasedtaper so that a-s the end of the feeding movement is reached, the cutterhead is raised to an extent so as to remove the cutter entirely from thedrillblank.

With the mechanism in this position, the rotation of the eccentricbearing journals into lowered position forces the drum gear 12 intoengagement with the gear 13 and consequently kdrives the gears 15 and11. This results in clockwise rotatio-n of the gear 11 which, being inlconstant en1.

gagement with gear 81, produces counterclockwise rotation of gear 81,and moves the :feeding sleeve 88 in the yopposite direction to movethecollet 84 Aand drill blank 95- back towardv their initial position.

As the gears 85 and 81, which are still-locked released for relativerotation with respect to the gear 81, the gear 81 engages the nuts |61to actuate control shaft |68 for releasing the eccentric bearing journalclutch andallowingthe pinion shaft and drum gear to rotate back towardthe position indicatedat A' in Figure 4. As aresult,

the drum gear 12 moves into meshing engagement with gear 85, and rotatesthis gear inthe opposite direction; that is, `a counterclockwisedirection, thereby bringing the plunger |81 into alinement with theplunger I8' f whereby the plunger i i8 moves into the-opening in thesupport |88of the plunger |81 to again lock the gears 85 and 81together. During this time, the gear 85 is being driven by the drum gear12 in a feeding direction, and due to the rotation -of the gear85, theplunger |81 moves into different alinement to produce the lockedposition indicated in Figure 5.v

At this instant the gear 85 drops off of the drum gear `12, allowing theeccentric journals to movel into full upper position, and the mechanismfeeds forwardly at a slow rate, being driven fromfthe pinion 18 and thegear 81. The rotation o-f the bearings has also produced disengagementofthe drum gear 2 from the gear13 so that the gear 81 merely rotatestheY gears 11,'15 and 13 idly about the shafts as the feeding movementprogresses.

It should also be remembered that as the eccentric bearing journalsrotate from their lower to their upper position they release the lowerend of the bell crank |52 Awhich in turn disengages the upper portion ofthis bell crank from the serrated surface of the shaft |58, therebyallowing spring |55 to draw the cam bar |44 back to a position loweringthe cutting mechanism into proper position for engaging the end of thedrill blank. The mechanism then again feeds forwardly to form the secondflute in the drill blank in the same manner as previously described.

As the plungerl |65r is engaged by the gear 81, the bearings againrotate to their lower-most position, and the gear 81v is reversed anddriven in a counter-clockwise direction by the gear 11 which is drivenfrom the drumkgear 12. However,

` this time when the plunger |81 engages the cam face |85 and therebyreleases the locking engage- 2,218,716 surface of the shaft |58V andthus locks vthe cam ment, by the gears 85 and 81, the'return of thebearings toward'their upper position produced .by engagement of gear 81with shaft |68"results in the pin |18 moving in a clockwisedirectionvandengaging the upwardly extending portion |12 of the bellicrank-BZ,thereby vrocking the bell crank inv a clockwise direction about thepivot 88 to lift .the locking end of the lever 55 from engagement -witharm 52. r-Ihis releases the rocking engagement of the clutch 48,' andthespring 58 is then effective to move the lever 155 back into the openvposition sho-wn inv Figure 1. This disengages the drivingmechanism fromthe power shaft, and consequently ystops the feeding mechanism so thatlthe drill may be removed and a new drill inserted.

yIf; vfor any reason, the friction clutches controlled by the plunger|65 and shaft |68 should.' vfail to operate and the feeding mechanismshould continue feeding the drill toward the cutter, the gear 81wilhengage the plunger |56, therebtr breaking contact between theconductors enclosed within the cable |13 leading to the control switch28 andwill stop the motor l2 so that no damage tothe mechanism .willoccur. This is merely* a safety feature to prevent overdriving of thefeed mechanism in case the friction clutchescontrolling-the eccentricvbearings should fail to operate. It is thereforev believed apparentthatI have provided a mechanism which is automatic in operation after thedrill blank has once been locked 1in position until completion of thefluting .operation. Thus an operator is able to supervise the operationof a plurality of such/machines since the only work required is theinserting and removall of the drill blanks, as the rest of theoperations -are all automatically controlled by Vthe mechanism hereindisclosed.

Of course I amaware that a number of changes vmay be made in certaindetails of construction of portions of the ,presentmechanism without inlany way departing from the underlying principles thereof,` and Itherefore do not intend to be limited except as dened by the scope andspirit of the appended claims.

` I claim:

' l. In combination, a rotating flute cutter, a rspindle adapted Atohave a drill blank locked in one end thereof, a feeding sleevesurrounding said spindle, means -for selectively indexing and lock` ingsaid sleeve to said spindle for conjoint rotation therebetween to feedsaid blank to said cutter, and means forreversing the rotation of saidisleeve upon predetermined feeding movement lment with said feedingmeans.

3. In combination, in a kdrill fluting mechanism, a main power shaftvincludinga pinion and a drum gear mounted on eccentric bearing journals,feeding means driven by said pinion, reversing means driven by said drumgear, and clutch means controlled by predetermined movement of saidfeeding means forv releasing said power shaft formovement on saidjournals to move said pinion into vinoperative position andsimultaneously' to move said drum gear into operative position. Y

4. The combination of claim 3 further characterized in the provision ofmeans operated by said drum gear at the end of reversing movement ofsaid reversing means for reindexing said feeding means.

5. In combination, in a drill fluting mechanism, a blank holdingspindle, a coaxial feeding sleeve mounted thereon, a rotatable cutterfor iluting the blank in said spindle, means supporting said cutter forvertical movement relative to the axis of said spindle, driving means,indexing means interlocking said sleeve and spindle for feedingVmovement toward said cutter, and means controlled bymovement of saidsleeve for simultaneously raising said cutter to decrease the effectivedepth of said flute Yas the blank is fed thereinto.

V6. In combination, in a drill fluting mechanism, a motor, a powershaft, feeding means for feeding a drill blank to a flute cutter, pinionmeans on said shaft for driving said feeding means, reversing meansdriven by saidshaft and automatically operable toI reverse said feedingmeans and reindex the same prior to a second feeding movement, means forclutching said motor to said shaft, spring means normally tending todisengage said clutch means, a latch for holding said clutch means inengaged position, and lever means actuated automatically upon the secondreverse movement of said feeding means for releasing' said latch toeffect disengagement of said clutch means.

7. In a feeding mechanism for a drill iluting machine, a spindle havinga collet at one end for gripping a drill blank, anindexing gear on saidspindle having circumferentially spaced axially projecting springpressed plungers, a feeding sleeve coaxially mounted on said spindle andhaving a spiral groove in the external surface there-- of, a journal forsaid sleeve and spindle having a fixed pin engaging in said groove, afeeding gear vfixed to said sleeve and rotated in one direction forfeeding said sleeve through said journal, a spring pressed plunger onsaid feeding gear adapted tointerlock selectively With said plungers onsaid indexing gear for locking said sleeve and spindle for conjointrotation, and cam means selectively engaged by said spaced plungers onsaid indexing gear for indexing said spindle in different positions tosaid sleeve.

8. The combinationl of claim 7 further characterized in means forselectively clutching said feeding gear to a driving pinion and to areversing train of gears to alternately feed said blank to a ilutingcutter and to Withdraw said blank vfrom said cutter for reindexing saidspindle with respect to'said sleeve.

9. The combination of claim 7 further characterized in the provision ofa drive shaft having alpinion for forward driving of said feeding gearand movable laterally of its axis on eccentric -drum gearonsaid shaftdisposed out of engagement with the other of said gears during drivingengagement of said pinion, an idler train of gears in constantengagement With said one gear, eccentric journals for said drive shaft,and means holding said drive shaft in one position in said journals andreleasable upon predetermined movement of said feeding means for movingsaid drive shaft to a second position to disengage said -pinion and movesaid drum into driving engagement with said train of gears for reversingthe direction of rotation of said one gear.

l1. The combination of claim l further characterized in the provision ofcam means for disvengaging said interlocked gears simultaneously withthe return of said 'drive shaft to its first position to effectengagement of said drum gear with said other gear for reindexing saidfeeding means and interlocking said coaxial gears prior -to a secondfeeding movement of said feeding means. r 112. The combination of claiml0 further characterized in the provision of means on said other gearfor releasing said clutch means upon the completion of the secondreversal of said feeding means.

13. In combination, in a drill iuting mechanism having blank feedingmeans automatically -driven in a feeding direction and then reversed toVa non-feeding position, an indexing gear plunger means connecting saidgear to said feeding means,

vcam actuated means responsive to nal reversing movement of said feedingmeans out of feeding position for releasing said plunger means torelease said indexing gear for rotation. relative to said feeding means,and spring means engaging said plungers for reconnecting said gear afterpredetermined relative rotation into a reindexing position to saidfeeding means prior to initiation 0f the next feeding movement thereof.

HABLAN E. MATTHEWS.

